Stomach: is in the gastric phase. MECHANICAL DIGESTION includes the three layers of muscularis externa. PROPULSION includes peristalsis and segmentation, and sphincters to prevent chyme from leaving the stomach. There is lots of CHEMICAL DIGESTION. HCL, protein (pepsin), gastric lipase (fat), chyme (food and acid), and digestion of proteins. SECRETION involves the gastric pit involving gastric glands, mucus cells which leads to mucus, chief cells which leads to pepsinogen, parietal cells which leads to HCL, and G cells which leads to gastrin. ABSORPTION includes lipid-soluble drugs, low levels of ethanol, and mucus covering epithelium; large marcomolecules.